The Mediterranean Sea was formerly of far greater extent than we see it to-day, and covered nearly the whole of northern Africa and the old upheaved sea-bottom that we see in the Desert of Sahara. Much of this great desert, as we know, has a considerable elevation, though part of it is still below the level of the Mediterranean.
Much of the country in the vicinity of New Madrid and Fort Donaldson was involved in these serious shocks. Swamps were upheaved and converted into dry uplands, while cultivated uplands were depressed below the average water level, and became swamps or ponds of water.
Again and again I have been part of an island, and then again sunk beneath the sea, to be upheaved again after long centuries, till I saw the light once more, and dropped from the face of some chalk cliff far away among high hills which have long since been swept off the face of the earth, and was tossed by currents till I became a pebble on the beach, while Reading was a sand-bank in a shallow sea.
The wilderness there is still a great wide moor-heath, about which we can read in the official description of districts. It is said that in old times there was here a sea, whose bottom was upheaved; now the moorland extends for miles on all sides, surrounded by damp meadows, and unsteady shaking swamp, and turfy moor, with blueberries and stunted trees.
In speaking of the elevation of the land having been slow, I do not wish to exclude the small starts which accompany earthquakes, as on the coast of Chile; and by such movements beds of shells might easily be uplifted, even in positions exposed to a heavy surf, without undergoing any attrition: for instance, in 1835, a rocky flat off the island of Santa Maria was at one blow upheaved above high-water mark, and was left covered with gaping and putrefying mussel-shells, still attached to the bed on which they had lived.
On her impetuous transit from Mr Bradshaw's to the Chapel-house, her wild, desperate thought had been that she would call herself by every violent, coarse name which the world might give her that Leonard should hear those words applied to his mother first from her own lips; but the influence of his presence for he was a holy and sacred creature in her eyes, and this point remained steadfast, though all the rest were upheaved subdued her; and now it seemed as if she could not find words fine enough, and pure enough, to convey the truth that he must learn, and should learn from no tongue but hers.
Nothing in Europe conveys a more striking sense of geological antiquity than such a prospect. The denudation and abrasion of innumerable ages, wrought by slow persistent action of weather and water on an upheaved mountain mass, are here made visible. Every wave in that vast sea of hills, every furrow in their worn flanks, tells its tale of a continuous corrosion still in progress.
All mountains and mountain-chains have been upheaved by great convulsions of the globe, which rent asunder the surface of the earth, destroyed the animals and plants living upon it at the time, and were then succeeded by long intervals of repose, when all things returned to their accustomed order, ocean and river deposited fresh beds in uninterrupted succession, the accumulation of materials went on as before, a new set of animals and plants were introduced, and a time of building up and renewing followed the time of destruction.
In more than one place we could almost fancy that some mountain has been upheaved and split asunder, the clefts formed by these gigantic fragments being now filled with veteran trees. The formation of the forest has puzzled geologists, to this day the origin of its rocky substratum remaining undetermined.
The basement of the icy pedestal on which the ships had been upheaved was gradually undermined, like the icebergs of the Arctic Ocean, by warm currents of water, and on the night of the 12th the huge block collapsed en masse, so that on the following morning nothing remained of the Dobryna and the Hansa except the fragments scattered on the shore.